In addition, as dietary energy balance is one of the few known modifiable factors associated with breast cancer progression, we assessed the effects of CR, with or without exogenous murine IGF-1 infusion, on mammary gland expression of cancer-related genes along with mammary tumor progression and cell signaling in an orthotopic MMTV-Wnt-1 transplant model. This evidence concerns the gene IGF1 and breast cancer.